Err msg causing conflict with other plugins

Hi and thanks for the helpful plugin. I have an error with the Membership plugin that I believe is causing a conflict with another plugin I’m using. The message I get is:
[24-Jan-2013 00:14:16] PHP Warning: Missing argument 2 for wpdb::prepare(), called in /home2/webcraf2/public_html/public_html/hilltoptest2/wp-content/plugins/membership/membershipincludes/classes/membershippublic.php on line 592 and defined in /home2/webcraf2/public_html/public_html/hilltoptest2/wp-includes/wp-db.php on line 990

I have built a site relying on Membership to display certain menu options depending on the level of the user and that part seems to be working fine. However, when Membership is activated it breaks the functionality of a plugin I use to display posts from a certain category (Advanced Recent Posts Widget). When Membership is deactivated, the other plugin works fine. I suspect that the above error message is causing the problem. Can you point me in the right direction for how to fix it? I am down to the wire on an installation that is supposed to take place in 2 days and have just discovered this conflict. Any help is appreciated!

Thanks,
Cindy Hood-Siegal

https://www.ads-software.com/extend/plugins/membership/